Why is ZM dropping frames for 1080p RSTP/MPEG4 and not MJPEG

[marcmerlin]

I don't understand this.
I have a Zavio F3210 where profile 1 is 1080p and if I setup good quality at even just 10fps, and use
rtsp://zavio-f3210-1:554/video.pro1 with ffmpeg in zoneminder, things work, but ZM gets partial frames where half the image is missing and filled with blur. Some frames are full, some are not.
I found that if I select the lowest quality in the camera and set 5fps, zoneminder mostly keeps up and video is ok, but even if I set my camera at 5fps, as soon as I set the quality back to high, I get partial frames.
There is gigabit ethernet between the machines, and the server is a quad core Intel(R) Core(TM) i3-2100T CPU @ 2.50GHz with linux.

My laptop can play that mpeg4 rtsp stream with VLC without problems, and I only get the partial frames when VLC see packet drop over wireless, which doesn't happen for the ZM server since it uses gige and the camera too.

Now, looking at http://www.zoneminder.com/wiki/index.php/Zavio I setup my camera to use much less efficient MJPEG at high bitrate. When I do that, ZM is able to show me the video without problems, even though the bandwidth used is a lot more, although it saves CPU I'm sure. ZM says it's able to capture the 15fps MJPEG stream at 5.82fps, so cleary it can't keep up, but because it's MJPEG, I don't get half frames.

So, it's better than nothing, but I'd much be able to use MPEG4 with RTSP, especially because now I'm forced to use MJPEG with vlc too, and it can barely keep up with MJPEG at 15fps in over RTSP.
Also, there is the problem that I'm now forced to disable sound because of this: http://www.zoneminder.com/forums/viewto ... 29&t=21026

When I was using rtsp with mpeg4, having sound on was not an issue.

So, can I do better, or is the best ZM can do with that camera?

Thanks,
Marc

[nikkolade]

I've now seen the very same problem with my two Foscam H.264 cameras. Based on some searching around the net & testing from command line, the problem definetely seems to lie in libav/ffmpeg.

If you try the viewing the rtsp-stream directly from the linux command line by using "ffplay", you'll most propably see that it doesn't work at all.

However, if you try the same rtsp-stream by using videolan ie. "cvlc", it works just fine.

Most of the current distros are currently using libav-tools instead of "original" ffmpeg and based on my very brief
testing it looks like the libav-tools rtsp-stream is completely unsable, while at least the GIT version of the ffmpeg seems
to work mostly ok.

I also checked the GIT version of avplay, and it only produces complete garbage especially with the FI8601W at 704x576 resolution.
The newer FI9802W works slightly better at 1280x720.

It would be nice to replace the rtsp-support from videolan libs instead of libav/ffmpeg ...

[marcmerlin]

Thanks for posting this. This made me realize that actually my foscam 9821 720p RTSP is also having sometimes the same problem, just a lot less often.
Strangely, I don't have the problem at all from my 720p RTSP stream from my ubiquity aircam dome. That's a bit puzzling...
But it looks like I have to go back to mjpeg for now.

Thanks